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Connecting
the
IoT
From BLE to 5G
—a look at the new networks
behind the next mega-trend:
the Internet of Things
May 2015
Smart
Bluetooth
Modules
Wireless Power
Amp Design
CONTENTS
CONTENTS
TECH SERIES
Wi GaN
Demystifying Wireless Power Amp Design
Figure 1: Class E and ZVS class D amplifier impedance capability superimposed on the A4WP class 3 standard Join Today
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IOT FEATURES
The Path to 5G
New Network Technologies That Will Power the IoT
Bluetooth Low Energy
Is it Most Suitable for IoT Applications?
The Future of the IoT
The Days of Limited Connectivity Are Over
4
10
16
22
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3
TECH SERIES
Wi GaN:
Demystifying A4WP-based 6.78MHz
Wireless Power Amplifier Design
The advent of portable electronics, most
notably the laptop and smartphone,
has revolutionized our lives. However,
portable electronics consume a large
amount of battery power, and while
engineers dedicate limitless hours to
optimizing battery life, battery life is still
a fundamental limitation to maximizing
user experience.
Ivan Chan
Field Applications Engineer
Michael A. de Rooij
Executive Director of Applications Engineering
Efficient Power Conversion Corporation
4
Wireless power transmission provides a
convenient alternative to the traditional
approach of wired charging. Gone will be
the days of carrying different adapters
and cables for your vast collection of
electronics. Instead, imagine a single
wireless charging device, which allows
simultaneous charging of multiple
products in its proximity, independent
of orientation and connector-type. This
vision is now a reality thanks to loosely
coupled A4WP-based wireless power
transfer, of which eGaN® FETs by EPC
are an enabling component.
Previous articles have discussed the
benefits of using eGaN FETs over
MOSFETs in both the Class E and
ZVS Class D topologies [1, 2]. It was
demonstrated that using eGaN FETs
in a ZVS Class D topology yielded an
amplifier that supported wider load
impedance ranges than the Class E
equivalent. This article will focus on
issues that are encountered after the
selection of topology and FETs.
5
TECH SERIES
Overcoming Load Impedance
Variation Effects
Peak efficiency of the Class E or ZVS Class D
amplifier occurs when it operates at resonance.
However, the amplifier in a loosely coupled
system rarely operates at resonance because in
order to allow the user to transfer wireless power
within a 3-dimensional region, the amplifier’s load
impedance varies considerably. The impedance
seen by the amplifier can be altered by any of the
following scenarios:
• Changing the distance and/or angle between
the source and receive coils of A4WPcompliant devices
• Variation in load current of the
A4WP-compliant receiver
• Placement of additional A4WP-compliant
receivers within the range of the source coil
• Placement of foreign metal or magnetic
objects within the range of the source coil
A4WP Class 3 Standard
The A4WP has defined a compliance window
of impedance values that a Class 3 amplifier
must be able to drive. The compliance window
consists of the impedance rectangle drawn
from (1 + 10j) Ω to (55 -150j) Ω and is depicted
as the shaded blue region in Figure 1 [3, 4].
Superimposing the results from [1] onto the
A4WP Class 3 impedance window shows
that further complexity to the amplifier is
required to drive the entire impedance window
efficiently. It is permissible to rotate the
class 3 impedance on the Smith Chart such
that the amplifier drives discrete segments of
the compliance window separately. By using
this technique, full compliance of
the A4WP standard is possible with a
single stage amplifier.
Adaptive Matching for
Optimizing Performance
The equivalent circuit of the reflected
impedance the amplifier will see due to various
situations described is shown in Figure 2.
As the reflected impedance varies, the operating
point moves further away from resonance thus
reducing system efficiency.
Since the 6.78MHz ISM bandwidth is only
+/- 15kHz, maintaining resonance by dynamically
adjusting operating frequency is not a viable
option. Alternatively, adaptive matching can
be used. Adaptive matching is the dynamic
adjustment of the series tuning capacitor value
based on variations in the loading of transmitter
coil LCoil.
An adaptive matching cell comprises a
bi-directional current blocking switch in series with
a tuning capacitor [5]. The FETs must have high VDS
rating, low COSS, and low RDS(on) to be effective. High
COSS can impact the tuning capacitor value, and
high RDS(on) lowers amplifier efficiency. As shown in
Figure 3, multiple adaptive matching cells can be
paralleled to further extend the efficient operating
range of the amplifier. The adaptive matching
controller would switch in the appropriate
capacitor value to adjust the coil impedance closer
to resonance. Adaptive matching also optimizes
coil efficiency as it narrows the operating
range of the coil such that it always operates
near resonance.
Summarizing the results of [1] in Figure 4 shows
that the ZVS Class D amplifier can drive a wider
impedance range than the Class E amplifier
can. Therefore, this implies that the ZVS Class D
amplifier would need fewer adaptive matching
cells to support the full +10 to -150j Ω range of
the A4WP Class 3 standard, resulting in a simpler
and more cost effective system solution.
EMI Generation Comparison Between
Class E and ZVS Class D
The spurious EMI emissions of the singleended Class E and single-ended ZVS Class D
amplifiers were simulated using LTSpice with
the amplifiers delivering 14 W into an A4WPcompliant load [5]. The results of the simulation
are shown in Figure 5. It can be seen that the ZVS
Class D amplifier does not output noticeable
even order harmonics, whereas the Class E
Figure 2: Simplified schemaDc of impedance variaDon on the Figure 1: Class E and ZVS class D amplifier impedance capability Figure 2. Simplified
due to load variaDon source schematic
coil LCoil of
impedance variation on
Figure 1. Class E and ZVS class D amplifier impedance drive capability
superimposed n the A4WP class 3 standard the source coil L due to load and operating variations.
superimposed
on the A4WP class 3ostandard.
Figure 3: MulDple adapDve matching cell topology Figure 3. Multiple adaptive matching cell topology.
Coil
6
7
TECH SERIES
outputs significant even order harmonics. Even
order harmonics impact the fundamental
asymmetrically and are difficult to filter out.
Therefore, EMI compliance for the ZVS Class D
is expected to be easier than it is for the Class E
amplifier [6].
Summary
Wireless power transfer is an effective way
to further enhance the usability of portable
electronics. But in order to wirelessly charge a
device, a reliable and convenient mechanism
is required. A4WP-based loosely coupled
wireless transfer has the potential to bring true
convenient wireless charging to next-generation
portable electronics. To help realize this vision,
eGaN FETs from EPC provide the most efficient
solution in 6.78MHz switching amplifiers.
This article identifies additional technical
challenges that would be encountered, namely
adaptive matching and EMI. Adaptive matching is
needed to extend the efficient operating range of
the amplifier to cover the A4WP Class 3 standard.
Also, simulated EMI spectrum show that the ZVS
Class D amplifier inherently has fewer even-order
emission spurs, making it easier to pass EMI
compliance limits. Please visitepc.co.com
epc-co.com for
more information.
References
[1] A. Lidow, “Wi GaN: eGaN® FETs Yield High Broad
Load Range Wireless Energy Transfer Efficiency,”
EEWeb: Wireless & RF Magazine, pg. 12 – 17, Aug 2014.
[2] A. Lidow, “How to GaN: Stable and Efficient ZVS
Class D Wireless Energy Transfer at 6.78 MHz,” EEWeb:
Pulse Magazine, Issue 126, pp. 24 – 31, July 2014.
[3] Alliance for Wireless Power (A4WP), Available:
http://www.rezence.com/
[4] A4WP Wireless Power Transfer System Baseline
System Specification (BSS), A4WP-S-0001 v1.2.1, May
07, 2014.
[5] M. A. de Rooij, Wireless Power Handbook: A
Supplement to GaN Transistors for Efficient Power
Conversion. El Segundo, CA: Power Conversion
Publications, 2015.
[6] M.A de Rooij, “Topology Performance Comparison
using eGaN® FETs in 6.78MHz Highly Resonant
Wireless Power Transfer,” DesignCon 2015, Santa Clara,
CA, 26-29 January 2015.
eGaN® FET is a registered trademark of Efficient
Power Conversion Corporation.
Figure 5(a): Simulated EMI current spectrum of Class E Figure 4: ZVS Class D versus Class E amplifier results Figure 4. ZVS Class D versus Class E amplifier results.
8
Figure 5a. Simulated EMI current spectrum of Class E.
Figure 5(b): Simulated EMI current spectrum of ZVS Class D Figure 5b. Simulated EMI current spectrum of ZVS Class D.
9
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13
MYLINK
MYLINK
IOT FEATURE
The
Path
to
5G
A Look at New
Network Technologies
That Will Power the IoT
In today’s mobile market, almost every device has wireless
capabilities on top of a Wi-Fi connection. These devices
use a certain generation of mobile telecommunications
technology; in the past several years, those technologies
have been referred to as 3rd Generation (3G), and
4th Generation (4G). 4G is the most advanced mobile
communications technology to date, but as technology
continues pressing forward, new features are being
discovered. With the rise of the Internet of Things and
various types of smart device technologies, it will take
something far more complex than 4G to bolster new
By Rob Riemen
EEWeb Contributing Author
wireless demands. The demand for a 5G network is
growing, but it may take years to implement in order
to power the rapidly expanding network of
connected devices.
16
17
IOT FEATURE
Adaptive-beam antennas use an
array of transmitters or receivers
to create a combined signal
that increases strength from a
starting point to a destination.
T
he 5G capability is more than
just anInternet connection.
It denotes a set of standards
that mobile devices and mobile
telecommunications use in relation
to services and networks that are
set by the International Mobile
Telecommunications-2000 (IMT2000) specifications through the
International Telecommunication
Union. The set of standards specifies
technologies involving voice, Internet
access, download and upload speeds,
and network protocols, among other
necessary mobile communication
technologies. Increased data speed
is an obvious improvement that
will be implemented with 5G, but
5G will be an amalgamation of
smarter technologies in order to aid
our daily lives. Three of the main
technologies being standardized
for the 5G upgrade are millimeter
wave wireless communications,
cognitive radio, and support for
the Internet of Things (IoT).
Millimeter Wave
Communications
Much of the improvements made
to wireless technology with the
adoption of 5G will be millimeter
wave wireless communications. In
order to understand the changes
that are occurring between current
technologies and future technologies,
you have to look back at the evolution
of 4G. Previously, the two forerunners
in technology when deploying 4G
platforms were Long Term Evolution
(LTE) Advanced and Mobile WiMax
(IEEE 802.16e). Currently, the 4G
18
standard for bandwidths is between 5
and 20MHz with a peak range of 40MHz.
Mobile WiMax can offer peak download
speeds of 128Mbit/s and upload speeds
of 56Mbit/s on these frequencies. WiMax
can achieve these speeds through scaling
of the fast Fouier transform, which
allow a higher bandwidth spectrum
efficiency in wide channels and cost
reduction in narrow channels. It also
uses adaptive antenna systems and
multiple-input multiple-output (MIMO)
technology. 4G LTE advanced can
deploy data rate speeds at a maximum
of 1Gbit/s downstream and 100Mbit/s
upstream on the previously mentioned
frequencies, which is accomplished
by using higher frequencies as well as
utilizing MIMO. MIMO uses multiple
transmit and receive antennas to exploit
multipath propagation. 5G will also
utilize these technologies, but with
modified versions. It is currently labeled
as a “converged fiber-wireless network.”
This will allow wireless Internet access
to use millimeter wave bands across the
20 to 60GHz spectrum. This frequency
range allows very wide bandwidth
radio channels and will support up
to 10Gbit/s of data access speed.
However, millimeter wave wireless
communications can be somewhat
limited. This is because frequencies
higher than 30GHz tend to be absorbed
by chemicals in the atmosphere such
as oxygen and water. Even water in
the form of humidity can absorb these
high frequencies. To combat these
interferences, this technology will have
to utilize adaptive-beam antennas.
Adaptive-beam antennas use an array
of transmitters or receivers to create
a combined signal that increases
strength from a starting point to a
destination. By deploying adaptivebeam antennas, networks can use
data transmission frequencies in the
range of 20-60 GHz to offer customers
up to 10Gbit/s without interference
from atmospheric elements.
Cognitive Radio
In keeping with the theme of frequency
channels, another way that 5G wireless
aims to be part of a smarter standard
is through the use of cognitive radio,
which is considered intelligent as it
can be programmed and configured
dynamically. This allows the smart
radio to find channels, and then
choose channels based on their
availability. Once a channel is chosen,
the radio then modifies connection
parameters in order to improve the
wireless communications. Operating
frequency, networking, waveform,
and protocol are the parameters
that cognitive radio is able to modify
automatically. Much of the work behind
cognitive radio deals with determining
the best operating frequency.
Cognitive radio uses spectrum
sensing and spectrum management
for optimal frequency selection. In
spectrum sensing, the antenna is trying
to find another nearby antenna with
similar broadcasting characteristics
as itself. This is done through several
avenues, starting with matched filter
detection, which uses a known signal
and correlates it with an unknown
19
IOT FEATURE
signal to detect the presence of certain
characteristics. Another avenue that
cognitive radio uses is energy detection,
where the antenna measures incoming
signals based on their energy output. If
the energy output is within the range of
what the antenna is expecting, then it
knows that it should use that incoming
signal. Spectrum management deals with
selecting the best range of signals to
meet current demand, without interfering
with current communications. This is
done by using energy sensors to detect
multiple signals and then employing
algorithms that distinguish which signals
are being used and which ones are not.
Even if a signal is not being used, it could
be weak for the purposes of what the
desired signal will be used for. Because of
cases like this and other factors like false
signals and required transfer amounts,
nodes have to be in constant contact
with each other. By using cognitive radio,
5G wireless standards aim to be much
smarter about choosing and utilizing
the best frequencies in order to have
information transfer fast and seamlessly.
5G and the IoT
to monitor important information.
Associated computers and devices can
then make decisions to better help our
lives. When 5G is implemented in 2020,
there has to be coverage for the demand
of billions of devices and simultaneous
connections. One of the technologies
being researched is what is referred
to as media-independent handover
(MIH). There are several layers involved
in wireless communications and the
ones used in MIH are layer 2 and layer 3.
Layer 2 is considered the data-link layer
whose job is to move data across the
network. Layer 3 is the network layer
concerned with IPs. The MIH has its
own specified function that helps with
the communication between multiple
different layers across different wireless
access points. When a user carries a
device across two access points with
different wireless technologies, MIH
assists with keeping the connection
seamless by converting information
across Layers 2 and 3. If devices on an
automated vehicle where to transfer
data from a private network to a public
network, MIH will be able to transfer
smoothly without the loss of data.
Perhaps the most popular network
trend right now is the Internet of Things.
Most of the current research for 5G
wireless standards is geared towards
what to expect and how to handle the
demand for the IoT. Devices of all kinds
are being connected to the Internet
By deploying a wide range of smart
technologies, server situations can
be handled much more efficiently.
When an ambulance needs to make
it to a hospital in as soon as possible,
traffic lights can sync up with where
By using cognitive radio, 5G wireless standards aim to be much
smarter about choosing and utilizing the best frequencies in
order to have information transfer fast and seamlessly.
20
the vehicle is located. This can be done by
using cameras and GPS sensors to accurately
pinpoint where the ambulance is located.
From here, multiple antennas can smartly
transfer their resources along the route of the
ambulance to determine what traffic lights
could hinder their progress. Other sensors
could determine what cars are in the way,
giving a heads up to the ambulance driver.
When 5G is implemented in 2020,
there has to be coverage for the
demand of billions of devices
and simultaneous connections.
Another wide use of the IoT with 5G wireless
will be automated vehicles. The sensors in
the vehicles will utilize the best frequencies
through spectrum management in order to
move the automated vehicle along. 5G can
also be implemented through the use of
wearables. For example, someone could be
monitoring their own vitals while shopping
for groceries; the wearables will utilize MIH
to transition networks to the user’s network
while also deploying spectrum management
to monitor ever changing human vitals. The
user can then be more informed as to what
foods to buy in order to be healthier.
These are just a fraction of the standards
to be implemented when 5G is rolled out
around the year 2020. Research is also being
done on dynamic ad-hoc wireless networks,
wireless network virtualization, multi-hop
networks and other technologies. The rollout
of 5G will combine these standards to provide
faster connections, smarter networking, and
device connection ability. The 5th generation
of wireless communication technology
standards will adhere to an ever-changing
interconnected world where multitudes of
data will be sent and received simultaneously
across a plethora of devices. By using smart
technologies through 5G wireless standards,
we will be able to live out our lives with the
ability to be more aware of the data around
us through seamless device integration.
21
IOT FEATURE
BLE
Is
MOST SUITABLE
for IoT Applications?
The Road to 50 Billion Smart-things
In 1999, eminent journalist Neil Gross stated,
“In the next century, planet earth will don an
electronic skin. It will use the Internet as a scaffold
to support and transmit its sensations. This skin
is already being stitched together.” True to Mr.
Gross’s expectations, today we are standing
face to face with the ultimate possibility of
a continuous skin: The Internet of Things.
By Anirban Sengupta
Cypress Semiconductor
22
23
IOT FEATURE
T
he Internet of Things (IoT) is often
defined as a scenario in which
objects, animals, and/or people are
provided with unique identifiers and the
ability to transfer data over a network
without requiring human-to-human
or human-to-computer interaction.
Cisco’s IBSG (Internet Business Solutions
Group) predicts that by the year 2020,
50-billion “things” will be connected
by the Internet of Things. The IoT is
driven by a combination of sensors
(or actuators), connectivity, and the
Internet. All the “things” that are to be
connected to the network are fitted with
sensors or actuators. The sensors talk
to the master devices (e.g. computers,
phones, etc.) using a communication
mode that is commonly understood
and detectable by the master.
The concept of the IoT, while
straightforward, leads to innumerable
possibilities. Take anything and fit a
sensor/actuator to it (the thing now
becomes a “smart-thing”). The sensor
detects and measures certain parameters
(example: heart rate, speed of running
/walking, where your pet is heading).
This data is wirelessly communicated
to a master (example: a phone or a PC).
Thus, the IoT is all about detecting,
measuring, and communicating.
For a successful IoT environment
to flourish, we need efficient and
cost-effective intercommunication
between masters and slaves as
well as between slaves themselves.
Communication is possible only when:
1.
One of the most celebrated
achievements of the entire IoT revolution
is the “cattle-sensors” invented by a
Dutch startup called Sparked. These
sensors, when connected to the ears
of cattle, can track an animal’s vitals
and message farmers when illness
or pregnancy is detected. As a result,
farmers can better control the health of
their livestock. Similar breakthroughs
have happened in other domains such
as healthcare (wireless cardiac monitor),
apparel (smart shoes), and consumer
electronics (smart refrigerators).
24
“Things” are active and
transmitting data
2. They are within the
communication range
3. There is interoperability
(i.e. the transmitted message
is understood by the receiver)
4. The data is relevant to the master
At the same time, it is important to
ensure that the communication process is
quick and doesn’t drain device batteries.
Wireless Communication Systems
Connectivity within the IoT often utilizes
wireless communication. There are
quite a few wireless communication
systems available to choose from.
Which communication technology is
the best fit depends on the application
type and its requirement. Based on
application needs, we can segment IoT
communication requirements as follows:
1.
Short range and long range: How far
can a device be from the master or
another device and still communicate
reliably? The previously mentioned
cattle example illustrates a longrange application. On the other hand,
there are numerous life-style, home
automation, PC peripheral, and health
applications where the need is for
short-range communication only.
2. Need for low-power communication:
When it comes to industrial
applications, there is a chance that
devices are wired to a power source
(or using a powerful battery) and thus
low-power communication may not
be required. However, for applications
like wearable electronics that
typically run on coin cell batteries,
the need for low-power
communication is acute. Such
applications are a major growth area
for the IoT in the coming years.
3. Short burst or continuous data transfer:
Some devices need to communicate
continuously while some devices need to
send data in short bursts periodically. The
metric used to describe these transfer
methods is duty cycle (= % of one period
when the signal is active). Thus, devices
can be segmented in terms of low or high
duty cycle.
The concept of the IoT,
while straightforward, leads
to innumerable possibilities.
4. Need for proprietary or standard
communication: There are many proprietary
(invented and owned by a single company)
and standard (specifications defined by
an industry body and multiple vendors
complying to the definition) communication
technologies available. One limitation
with proprietary communication is the fact
that both parties (master-slave, mastermaster, or slave-slave) need to be similarly
equipped to acknowledge and interpret
the data. This can usually happen when the
transmitter device and receptor device are
both manufactured by the same company
or by companies that have co-developed
a solution (e.g., a PC by company X can
talk to wireless mice by company X using
a particular proprietary communication
technology).
25
IOT FEATURE
However, with more and more new IoT
devices entering the market, the scope of
proprietary communication technology
begins to limit the marketability of
devices. To understand this better,
let’s consider the wearable technology
segment. There are many companies
focused on creating innovative smart
wearable devices. Most of these
companies do not manufacture master
devices such as PCs or smart phones.
These companies would thus prefer
that their devices can talk to maximum
number of masters. For this they would
use a standard communication that
most master devices can understand.
With more
and more new
IoT devices
entering
the market,
the scope of
proprietary
communication
technology
begins to
limit the
marketability
of devices.
Bluetooth Low Energy (BLE)
Bluetooth Low Energy or BLE (marketed
as Bluetooth smart) is a wireless
communication technology designed
and marketed by the Bluetooth
SIG. BLE is targeting
applications that have the
following requirements:
1.
3. Multi-vendor interoperability: As
a standard, BLE, like the previous
versions of Bluetooth, enjoys a high
level of adoption by master-device
manufacturing companies. Many
IOT slave devices also support BLE.
Key operating systems like Android,
iOS, Windows 8, and Linux natively
support BLE. The SIG predicts that
by 2018, 90% of smart phones will
support BLE. This ecosystem helps
achieve multi-vendor interoperability.
4. Data transfer up to 1Mbps:
A BLE stack (Figure 1. Stack diagram)
comprises three sub-groups:
Range of up to 100m:
However, as per the SIG
website, the specification
does not limit range. This
means manufacturers can
possibly create devices
that have range higher
than 100m.
2. Need to run on coin cell
battery for significant time:
Many IoT devices need to
be able to run on standard
coin cell batteries for years.
BLE enables ultra-low
26
peak, average, and idle mode power
consumption. In addition, devices with
a lower duty cycle will save
more power.
Figure 1. BLE stack diagram
A. Controller: The actual device
that encodes the data packet
and transmits it as a radio signal.
The controller is also capable
of receiving radio signals and
decoding them for data.
B. Host: It is the software stack,
consisting of protocols and profiles
(a collection of services and their
behavior that together perform a
particular end application), that
manages the communication
between two devices.
C. Application: A use case that
utilizes the controller and host to
implement a particular function.
The application layer is a great advantage
of Bluetooth. For developers, it means
that along with the generic set of
protocols and services, they have access
to many application-specific protocols.
The Bluetooth SIG has defined several
profiles (i.e., a specification of how a
device would function in a particular
application) for BLE devices. An example
would be HRP or heart rate profile. This
profile enables a collector (say a smart
phone) to connect and interact with a
Heart Rate sensor placed on a user’s body.
The profile specifications released by the
SIG state the profile dependencies (e.g.
HRP requires a generic attribute profile
or GATT), sensor role requirements,
collector (data) role requirements,
connection establishment procedure, and
security considerations, among others.
Adhering to the profile specs makes
the process of qualifying BLE for an
application seamless and easy. The SIG
webpage lists all the available profiles. A
device may make use of multiple profiles.
BLE Against the Rest
(for IoT Applications)
Today the top competitors to BLE
are ZigBee, Wi-Fi, Ant+ and a wide
range of proprietary protocols. Let’s
understand the competition briefly
before getting into a formal comparison:
ZigBee is a wireless communication
specification developed by the
ZigBee alliance, a non-profit
association with close to 400
members. ZigBee supports a large
network with multiple low power
chipsets operating at a lower data
rate than BLE. ZigBee primarily
targets home automation and
industrial automation systems.
Today
the top
competitors
to BLE are
ZigBee,
Wi-Fi,
Ant+
and a wide
range of
proprietary
protocols.
Wi-Fi is a wireless networking technology
that uses radio waves to provide
high speed internet and network
connectivity. It is based on IEEE
802.11 standards and consumes much
more power than ZigBee or BLE.
ANT+ is an interoperable open-access
wireless sensor network technology
designed and marketed by ANT
Wireless (a subsidiary of Garmin
since 2006). Low power is one of the
key USPs of ANT. Typically, ANTenabled devices are expected to
be in sleep mode for long periods,
wake up briefly to send data, then
return to sleep mode again. It targets
sports and fitness applications.
27
IOT FEATURE
BLE is the best choice when it
comes to setting up a personal
network by connecting a batterybacked smart device to a single
phone or computer wirelessly.
Comparing BLE with proprietary
protocols would be unfair. Any
application that intends to use a
standard communication technology
would abstain from using a proprietary
protocol. Thus, the comparison will
be limited to four standard players
only: BLE, ZigBee, Wi-Fi and ANT+.
The first parameter we need to
consider while comparing the above
communication technologies is the
type of network our devices will join.
IoT devices may connect to a PAN
(Personal area network) or WLAN
(wireless Local area network). When a
device is connecting to the WLAN, Wi-Fi
is definitely the best option in terms of
cost. However, the power consumption of
Wi-Fi is high and thus we cannot expect
devices that need to run on coin-cell
batteries to connect to a LAN using Wi-Fi
(unless we have a plan in place to replace
batteries periodically.) Thus, devices that
are constrained in terms of power can
only connect to a LAN indirectly. That is,
they connect to a master (e.g., a smart
phone or PC) and let the master connect
to a LAN. In addition, one advantage
of using a LAN is resource sharing (e.g.
shared enterprise printers). However,
most IoT devices don’t actually need this
advantage – a heart rate sensor needs
to connect to only one master device.
Thus the ideal network for most
battery-backed IoT devices that
need to communicate with a single
master is PAN. This reduces our
choice for communication standard
to BLE, Ant+ and ZigBee.
28
The competition between ANT+ and
BLE is extremely interesting. ANT+
lists BLE as a competitor
but BLE
competitor
doesn’t acknowledge ANT+ in its list of
competitors.
competitors ANT’s one-sided paranoia
about BLE stems from the fact that
BLE targets ANT’s market almost to
entirety. ANT+ and BLE are competitive
in terms of key specs such as over the
air data rate, application throughput,
and range (50-100m). However BLE
still corners ANT+ in terms of actual
industry adoption. Please note, on their
own BLE and ANT are nothing beyond
protocols. Their real success depends
on how much industry adoption they
enjoy. Industry adoption is dependent
on the number of chipmakers willing to
invest in designing and manufacturing
chips that support a protocol, the
number of master devices supporting
the protocol natively, and of course
the number of slave manufacturers
willing to take a bet on the technology.
As of today, there are only three
manufacturers who are supplying chips
with ANT+: Dynastream Innovation,
Nordic Semiconductor, and Texas
Instruments. In the case of BLE, there
are planned or in-production chips from
Broadcom, Freescale, Cypress, Microchip,
Bluegiga, StMicro, Dialog Semiconductor
and many others (including TI and
Nordic). In fact, TI and Nordic are the only
manufacturers whose portfolio has ANT+
enabled chips, BLE enabled chips, and
chips with both technologies supported.
Currently, all the major mobile operating
systems (iOS, Android, Windows,
Blackberry) natively support BLE. In
the case of ANT+, native support is
limited. Windows8 and iOS both don’t
support ANT+ natively. Thus, to pair an
ANT+ device with a Windows phone
or an iPhone requires an additional
ANT+ USB stick or dongle. In the case
of Android, there are plug-ins available
to run ANT+, if the phone manufacturer
supports the same. As of now,
Samsung and Sony are the major phone
manufacturers supporting ANT+ across
a wide product range. However, support
for ANT+ doesn’t rule out support
for BLE. In fact, the update enabling
ANT+ on the Samsung devices was a
part of Android 4.3 update – the same
update brought full Bluetooth smart
compatibility to these devices as well.
ANT+ targets the sports, fitness, and
lifestyle market primarily. The end goal
of the technology would be to ensure
that the maximum number of smartdevice makers in this category choose
it for communication. ANT+ was indeed
successful till BLE was launched. Post
the launch of BLE, the manufacturers of
this category now had an alternate choice
in terms of low-power communication
protocols. Since BLE is backed more by
the masters, it proved to be a safer bet.
Thus, major wearable makers like Fitbit,
Jawbone and Tom-tom have all chosen
BLE. And, of course, the much-celebrated
Apple watch will use BLE to pair with
iPhones. Since BLE is expected to be a
standard for almost all smartphones
in the near future, smart devices are
also expected to follow suit. However,
ANT+ may survive as a niche protocol for
29
TECH REPORT
applications where BLE cannot perform
(e.g., point to multipoint communication
or single slave to multiple master
communication is not possible in BLE
but can be done through ANT+).
The battle between BLE and ZigBee is
on a different turf – home and industrial
automation. BLE cannot displace ZigBee
entirely. This is because ZigBee allows
mesh networking while BLE is restricted
to a star network topology (i.e., many
slaves connecting to a single master).
Also, ZigBee allows connection of more
devices than BLE. These features make
ZigBee a better choice when a bigger
range network is required. On the other
hand, to connect simple devices to a
phone BLE would be more convenient
due to its large existing installed base. In
addition, the data rate and throughput
of BLE is better than ZigBee. Setting up
a ZigBee network requires connecting
an additional ZigBee modem to a host
device (preferably a PC) and thus it is
less convenient and more expensive
than setting up a BLE network.
In summary, BLE is the best choice
when it comes to setting up a personal
network by connecting a batterybacked smart device to a single
phone or computer wirelessly. Thus,
it is becoming the communication
protocol of choice for an increasing
number of smart wearables, PC/Phone
peripherals, and health monitoring
equipment. The Bluetooth SIG website
lists
lists the various Bluetooth Smart Ready
products (host devices that support
BLE) and Bluetooth Smart products
(independent devices that communicate
with the host using BLE). The list is ever
increasing and is indicative of the bright
future of BLE in IoT applications.
To learn more about BLE and get
started with your own design, see the
following application note: http://
http://
www.cypress.com/?docID=51385
www.cypress.com/?docID=51385
About the Author
Anirban Sengupta works as a pricing manager
at Cypress Semiconductor. He holds a BE in
Electrical Engineering from National Institute of
Technology, India and an MBA in Marketing from
Symbiosis Centre for Management and Human
Resource Development (SCMHRD), Pune, India.
30
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IOT FEATURE
The
Future
Internet
of the
of Things
The days of computers,
smartphones, and tablets
being connected only
to the Internet are over.
By Roger Ordman
Redbend
It is no secret that the Internet of Things (IoT) is
continuously growing and is viewed by many as the next
big advancement of the Internet. But what exactly is the
IoT, and in what ways will it affect the future of everyday
lives? According to TechTarget1, the IoT is defined as
“a scenario in which objects, animals or people are provided
with unique identifiers and the ability to transfer data
over a network without requiring human-to-human or
human-to-computer interaction.” Many experts2 believe
that the IoT will be thriving by 2025, and the resulting
growth in connectivity will influence everything, from
household appliances to agriculture.
32
33
IOT FEATURE
As more and more devices become
Internet-connected, device manufacturers will need
to consider how to manage and update everything.
P
art of the IoT’s growth will be
exemplified by the amount of
connected devices in play. In
fact, Cisco IBSG predicts3 there will be
25 billion devices connected through
the Internet by 2015, and 50 billion
connected devices by 2020. With this
ongoing growth of connectedness,
the world needs to consider the
effects of this level of connectivity.
The days of computers, smartphones,
and tablets being connected only to
the Internet are over. For example,
smartphones are now able to connect
to cars in order to play music via apps.
We can now also use an app to change
the channel on our televisions, or to
record a show. Being able to control
different devices is already at our
fingertips, literally. In the near future,
the amount of “things” we will be
able to control through the Internet
and connected devices will go beyond
what we are currently able to do with
our smartphones and tablets.
As more and more devices
become Internet-connected,
device manufacturers will need to
consider how to manage and update
everything. The mobile industry
uses OTA updates to manage devices
throughout their lifecycle, pushing
out updates as frequently as needed
to ensure the best user experience for
its customers.
34
There are three elements of OTA
updating systems: the update generator,
software management center, and update
installer. The update generator identifies
and extracts the fundamental changes
between the existing and the updated
version, while creating a delta package
with the updated file of all the changes.
This delta package holds information that
affects device appearance, configuration
and branding.
After the delta package has been created,
the file is sent to the device using a
communications protocol, which is used
by a back-end software management
center to enable original equipment
manufacturers (OEMs) to centrally
manage firmware, applications, and
mobile devices over the air. A protocol
optimized for mobile communication
known as the open mobile alliance device
management (OMA DM) standard is used
to communicate between the software
management center and an OMA DM
client on the device. This protocol
provides all the management aspects of
the software updating process.
Over-the-air updating can be used across
all devices, as it is easy, beneficial, and cost
efficient. As this form of updating makes
its way into relevant industries such as the
automotive industry, consumers will soon
expect this type of efficient updating for all
their connected devices, regardless of the
size, shape, or cost.
There’s no doubt that the future of the IoT
is bright, and with OTA technology, we’re
able to ensure our connected devices are
updated continuously, safely, efficiently,
and securely.
Web References
http://whatis.techtarget.com/definition/
1. http://whatis.techtarget.com/definition/
Internet-of-Things
Internet-of-Things
http://www.pewinternet.org/2014/05/14/
2. http://www.pewinternet.org/2014/05/14/
internet-of-things/
internet-of-things/
www.cisco.com/web/about/ac123/ac147/
3.
www.cisco.com/web/about/
archived_issues/ipj_15-3/153_internet.html
ac123/ac147/archived_issues/ipj_
15-3/153_internet.html
After the device successfully receives the
delta package, software on the mobile
device, known as the firmware over-theair (FOTA) update installer, performs
the update installation with the new
delta package. This installer updates the
device’s firmware reliably.
35
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